The present invention relates generally to hydraulic cylinder control mechanisms and, more particularly, to a control linkage for limiting the extension and retraction strokes of a hydraulic cylinder.
Hydraulic cylinders are used on equipment such as agricultural implements to selectively permit a movement of one component relative to another. On some equipment, such as a unitizing raking implement, it is desirable to move one component consistently to a preselected position; however, where the selected position can be set at a variable location between the fully retracted and the fully extended limits of the hydraulic cylinder, it is necessary to provide a stroke control limiter to restrict the movement of the hydraulic cylinder beyond a certain length of stroke.
Prior art stroke limiters generally utilize collars that mount around the rod member of the hydraulic cylinder. Such collar limiters change the length of the retraction stroke of the hydraulic cylinder by preventing the rod member from fully retracting into the hydraulic cylinder barrel. Collar limiters do not vary the extension stroke of the hydraulic cylinder from a fully retracted position. These mechanisms do not allow for a variable adjustment that is needed in certain equipment applications. Accordingly, it would be desirable to provide a stroke limiting mechanism for a hydraulic cylinder that can be selectively positionable to permit a full retraction of the rod member into the cylinder barrel, as well as limit the length of both the extension stroke and the retraction stroke of the hydraulic cylinder.